marine corps base, quantico shoreline protection plan · 2020-04-16 · 1 introduction 1.1 shore...

March 2011

Shoreline Studies ProgramVirginia Institute of Marine Science

College of William & MaryGloucester Point, Virginia

Marine Corps Base, QuanticoShoreline Protection Plan

Marine Corps Base, QuanticoShoreline Protection Plan

Shoreline Studies ProgramVirginia Institute of Marine Science

College of William & MaryGloucester Point, Virginia

Final Report

March 2011

i

Table of Contents

Table of Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . i

List of Figures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ii

List of Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ii

1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.1 Shore Setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.2 Statement of the Problem and Goals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

2 Shore Management Strategies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

3 Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23.1 Photo Rectification and Shore Change . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23.2 Wave Climate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33.3 Existing Conditions Survey and Shore Management Strategy Development . . . . . . . . . . . . . 3

4 Physical Setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54.1 Geology and Shoreline Change . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54.2 Wave Climate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54.3 Tide and Storm Surge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64.4 Sea-Level Rise . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

5 Reach 1: Potomac River South of Chopawamsic Creek . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65.1 Shore Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

5.1.1 Reach Boundaries and Shore Change . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65.1.2 Upland and Shore Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65.1.3 Nearshore Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

5.2 Design Considerations and Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

6 Reach 2: Chopawamsic Creek . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86.1 Shore Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

6.1.1 Reach Boundaries and Shore Change . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86.1.2 Upland and Shore zone Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86.1.3 Nearshore characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8


7 Reach 3: North of Chopawamsic Creek to the Marina . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97.1 Shore Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

7.1.1 Reach Boundaries and Shore Change . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

7.1.2 Upland and Shore Zone Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97.1.3 Nearshore Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9


8 Reach 4: North of the Marina to Quantico Creek . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108.1 Shore Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

8.1.1 Reach Boundaries and Shore Change . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108.1.2 Upland and Shore Zone Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108.1.3 Nearshore Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

8.2 Design Considerations and Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

9 Reach 5: Quantico Creek . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

10 Summary and Cost of Structures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

11 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

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List of Figures

Figure 1-1. Location of Marine Corps Base, Quantico within the Chesapeake Bay estuarine system . . . . 16Figure 1-2. Boundaries of MCB, Quantico and the Town of Quantico. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16Figure 2-1. Sand fill with stone sills and marsh plantings at Webster Field Annex, St. Mary’s County,

Maryland A) before installation, B) after installation but before planting, C) after four years, and D) the cross-section used for construction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Figure 2-2. Breakwater system on Patuxent River in Calvert County, Maryland and a typical breakwatercross-section. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Figure 2-3. A) Stone revetment shortly after construction on the Potomac River, Virginia, and B)cross-section of the elements necessary for proper stone revetment design (Hardaway and Byrne,1999). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Figure 2-4. Shore-attached and structure-attached spurs used as part of a shore protection system at PointLookout, Maryland. Photo date 12 Jan 2006. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Figure 2-5. Location and density of submerged aquatic vegetation at MCB, Quantico as mapped by theVirginia Institute of Marine Science in 2009 (http://web.vims.edu/bio/sav/maps.html). . . . . . . . . . 19

Figure 3-1. Index of plates used to display historical and recent aerial imagery and the rates of shorelinechange. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Figure 3-2. Location of STWAVE grids and data output stations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20Figure 3-3. Index of plates used to display shore management recommendations and the shore reaches used

in the discussion of the reaches. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20Figure 4-1. Geologic strata map of Marine Corps Base, Quantico. GIS data provided by Quantico. . . . . . 21Figure 5-1. Bank conditions and recommended shore management structures for Plates 1 and 2. . . . . . . . 22Figure 5-2. Bank conditions and recommended shore management structures for Plates 3 and 4. . . . . . . . 23Figure 5-3. Photos taken along Quantico’s shoreline in Reach 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24Figure 5-4. Shore management strategy cross-sections for Reach 1A. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25Figure 5-5. Shore management strategy cross-sections for Reach 1B. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26Figure 6-1. Bank conditions and recommended shore management structures for Plates 5 and 6. . . . . . . . 27Figure 6-2. Photos taken along Quantico’s shoreline in Reach 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28Figure 6-3. Cross-sections of typical structures for Reach 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29Figure 7-1. Bank conditions and recommended shore management structures for Plates 7 and 8. . . . . . . . 30Figure 7-2. Bank conditions and recommended shore management structures for Plates 9 and 10 . . . . . . 31Figure 7-3. Photos taken along Quantico’s shoreline in Reach 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32Figure 7-4. Typical cross-sections for recommended structures in Reach 3. . . . . . . . . . . . . . . . . . . . . . . . . 34Figure 8-1. Bank conditions and recommended shore management structures for Plates 11 and 12 . . . . . 35Figure 8-2. Photos taken along Quantico’s shoreline in Reach 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36Figure 8-3. Typical cross-sections for management strategies recommended in Reach 4. . . . . . . . . . . . . . 37Figure 9-1. Bank conditions for Plates 13 and 14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38Figure 9-2. Bank conditions for Plates 15 and 16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39Figure 9-3. Photos taken along Quantico’s shoreline in Reach 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

List of Tables

Table 3-1. Wind wave conditions input to the STWAVE hydrodynamic model . . . . . . . . . . . . . . . . . . . . . . 3Table 4-1. Wave conditions resulting from STWAVE modeling of the southerly wind/wave climate . . . . . 5Table 4-2. Wave conditions resulting from STWAVE modeling of the northeasterly wind/wave climate . . 5Table 4-3. Storm surge elevations at the confluence of Chopawamsic Creek and the Potomac River

(FEMA, 1995) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6Table 10-1. Summary of recommended structures for Quantico’s shoreline with estimated costs by

Reach and by priority. Costs are conceptual estimates based on recommended structure cross-sections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Table 10-2. Material and cost estimate summary for Reach 1. Costs are conceptual estimates based on recommended structure cross-sections. Amount of cut/fill from the bank was difficult todetermine and is an estimate only. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Table 10-3. Material and cost estimate summary for Reach 2. Costs are conceptual estimates based on recommended structure cross-sections. Amount of cut/fill from the bank was difficult todetermine and is an estimate only. . . . . . . . . . . . . 13

Table 10-4. Material and cost estimate summary for Reach 3. Costs are conceptual estimates based on recommended structure cross-sections. A Amount of cut/fill from the bank was difficult todetermine and is an estimate only . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Table 10-5. Material and cost estimate summary for Reach 4. Costs are conceptual estimates based on recommended structure cross-sections. Amount of cut/fill from the bank was difficult todetermine and is an estimate only . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Table 10-6. Summary of cost estimate by reach. Costs are conceptual estimates based on recommended structure cross-sections. A recent survey and updated design is needed to determine actual costs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

http://web.vims.edu/bio/sav/maps.html

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1 Introduction

1.1 Shore Setting

Marine Corps Base, Quantico (MCB, Quantico or Base) is located on the Potomac River in Virginiaabout 35 miles south of Washington, D.C. and 20 miles north of Fredricksburg, Virginia (Figure 1-1). TheBase covers nearly 100 square miles in Prince William, Stafford, and Fauquier Counties. It has almost fivemiles of shoreline along the Potomac River and a little more than two miles on Quantico Creek. In addition,Chopawamsic Creek is included within the base (Figure 1-2).

1.2 Statement of the Problem and Goals

MCB, Quantico is a major U.S. Marine Corps training base for both amphibious warfare and air-support tactics. A great deal of infrastructure is directly adjacent to the shoreline. As such, shore changelikely has been an issue since the Base’s inception in 1917 as evidenced by the many fill projects anderosion control structures that have been placed along the shoreline.

Many areas of Quantico’s shoreline already have protection, particularly the areas that haveinfrastructure. However, those structures, mostly revetments of broken concrete and concrete and stonewalls, are old and deteriorating. Broken concrete revetments are not standard engineered structures, andmany structures could use rehabilitation. Other areas of the Base have exposed high banks that are activelyeroding and threatening upland infrastructure.

One goal of this management plan is to provide more habitat-friendly management strategies whichutilize the creation of marshes and beaches for shore protection rather than hardening the coast. Many ofthese strategies have been implemented around the Bay. These approaches include creating a marsh fringeby direct planting of the existing substrate, adding sand, and adding sand with stone sills. On more opencoasts, breakwaters and beach fills can be built to achieve a stable sandy habitat of beaches and dunes. These “Living Shoreline” strategies can, if properly designed and constructed, provide shore protection aswell as create a viable vegetated fringe that 1) restores natural functions and 2) provides a water qualitybuffer. The fundamental objective of the living shoreline approach is to protect eroding shorelines whilealso enhancing water quality and habitat for living resources in the Bay.

2 Shore Management Strategies

In developing the Shoreline Management options for effective shore stabilization, the followingobjectives (Hardaway and Byrne, 1999) should be given consideration:

• Prevention of loss of land and protection of upland improvements.• Protection, maintenance, enhancement, and/or creation of wetland habitats, both vegetated and non-

vegetated.• Management of upland runoff and groundwater flow through the maintenance of riparian and

vegetated wetland fringes.• For a proposed shoreline strategy, address potential secondary impacts within the reach which may

include impacts to downdrift shores from a reduction in the sand supply or the encroachment ofstructures onto subaqueous land and wetlands.

• Abatement of sedimentation through erosion control. • Longevity of the shore stabilization strategy.

These objectives are best assessed initially in the context of a shoreline reach. While all objectivesshould be considered, they will not carry equal weight. In fact, satisfaction of all objectives for any givenreach is not likely as some may be mutually exclusive. Suitable shoreline management strategies forQuantico are listed below.

1) Stone sills: The stone sill has been used extensively in Chesapeake Bay (Figure 2-1). It is a rockstructure placed parallel to the shore so that a marsh can be planted behind it. The cross-sectionshows the sand for the wetland substrate is on about a 10:1 slope from the base of the bank to theback of the sill. The elevation of the intersection of the fill at the bank and tide range will determine,in part, the dimensions of the sill system.

2) Breakwater System: Although single breakwaters can be used, two or more are recommended toaddress several hundred feet of coast (Figure 2-2). For breakwaters, the level of protection changeswith the system dimensions such that larger dimensions generally correspond to bigger fetches andwhere a beach/dune shoreline is desired.

3) Revetments: Many bulkheads and revetments exist along the Quantico coast, some of which are inneed of repair or extensions (Figure 2-3). Stone revetments may be the preferred method for shoreerosion control along high banks or where vital infrastructure is located close to the shoreline. It isusually the preferred strategy when hardening of the shoreline is required

4) Spurs: A spur is a structure that is connected either to the land or another structure (Figure 2-4). Spurs can be used to maintain a certain beach width or at the end of sills or breakwaters to mitigatedowndrift impacts.

2

The overall goal of effective shoreline strategies, other than defensive structures, is to create a lesssteep coastal gradient. On the landward side, this reduces erosion from runoff; on the seaward side, waveenergy is reduced before it impacts the bank. However, creating these more gradual slopes can involveencroaching into landward habitats (banks, riparian, upland) through grading and into nearshore habitats byconverting existing sandy bottom to marsh or rock.

Balancing the encroachment is necessary for overall shoreline management. Bank grading may benecessary for unstable banks to reduce their slope and minimize the risk of bank failure. Newly gradedslopes should be replanted with different types of vegetation including trees, shrubs and plants. Marshes aregenerally constructed on slopes between 8:1 and 14:1, but average about 10:1 (for every 10 ft in width, theelevation changes by 1 foot). Steeper systems have less encroachment into the nearshore but may notsuccessfully stabilize the bank because the marsh may not attenuate the waves enough before they impactthe bank. Shallower, wider systems have more encroachment but also have the advantage of creating moremarsh and attenuating wave energy more effectively. Determining the system’s level of protection, i.e.,height and width, is the encroachment.

The location of submerged aquatic vegetation (SAV) must also be considered in the placement ofstructures in the nearshore. At Quantico, the nearshore is heavily covered in SAV (Figure 2-5) whichcomplicates obtaining permits for structures in the nearshore. Various species cover the nearshore at 70%-100% density. These species are Ceratophyllum demersum (coontail), Heteranthera dubia (waterstargrass), Hydrilla verticillata (hydrilla), Myriophyllum spicatum (Eurasian watermilfoil), Najasguadalupensis (southern naiad), Najas minor, and Vallisneria americana (wild celery) (SAV, 2007). Moreinformation on SAV types can be found at http://web.vims.edu/bio/sav/species_classification.html.

3 Methods

3.1 Photo Rectification and Shore Change

In order to understand the suite of processes that work to alter a shoreline, knowledge of the historyof shoreline change is essential. Often analysis of aerial photographs provides the historical data. Imagesof Quantico from 1937, 1996, 1999, 2002, and 2009 were used in the analysis. The 1937 photos wererectified by VIMS using the procedure below. The 1996 and 1999 images were provided in GIS format byQuantico. One photo tile in the 1999 image series was missing. The 2002 and 2009 imagery wereorthorectified by the Virginia Base Mapping Program (VBMP).

The 1937 images were scanned as tiffs at 600 dpi and converted to ERDAS IMAGINE (.img)format. They were orthorectified to a reference mosaic, the 1994 Digital Orthophoto Quarter Quadrangles(DOQQ) from USGS. The original DOQQs were in MrSid format but were converted into .img format. ERDAS Orthobase image processing software was used to orthographically correct the individual flightlines using a bundle block solution. Camera lens calibration data were matched to the image location offiducial points to define the interior camera model. Control points from 1994 USGS DOQQ images providethe exterior control, which is enhanced by a large number of image-matching tie points producedautomatically by the software. A minimum of four ground control points was used per image, allowing twopoints per overlap area. The exterior and interior models were combined with a digital elevation model(DEM) from the USGS National Elevation Dataset to produce an orthophoto for each aerial photograph. The orthophotographs that cover each USGS 7.5 minute quadrangle area were adjusted to approximatelyuniform brightness and contrast and were mosaicked together using the ERDAS Imagine mosaic tool toproduce a one-meter resolution mosaic also in .img format. To maintain an accurate match with thereference images, it was necessary to distribute the control points evenly. This can be challenging in areaswith little development. Good examples of control points are manmade features such as corners ofbuildings or road intersections and stable natural landmarks such as easily recognized isolated trees.

Once the 1937 aerial photos were orthorectified and mosaicked, the shoreline was digitized inArcMap with the mosaic in the background. This procedure also occurred for the 1996, 1999, 2002, and2009 mosaics. The toe of the narrow beaches, which can indicate the position of low water, was delineatedas the shoreline. In areas where the shoreline was not clearly identifiable on the aerial photography, thelocation was estimated based on the experience of the digitizer. The displayed shorelines are in shapefileformat. The photos and shorelines are displayed using a set of four plates created along the shoreline(Figure 3-1). The images and the shorelines are shown in Appendix A.

Horizontal positional accuracy is based upon orthorectification of scanned aerial photography usingUSGS DOQQs. Vertical control is the USGS 100 ft (30 m) DEM. The 1994 USGS reference images weredeveloped in accordance with National Map Accuracy Standards (NMAS) for Spatial Data Accuracy at the1:12,000 scale. The 2002 and 2009 Virginia Base Mapping Program's orthophotography were developed inaccordance with the National Standard for Spatial Data Accuracy (NSSDA). Horizontal root mean squareerror (RMSE) for the 1937 mosaic was held to less than 20 ft (6 m).

http://web.vims.edu/bio/sav/species_classification.html

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Using methodology reported in Morton et al. (2004) and National Spatial Data Infrastructure (1998),estimates of error in orthorectification, control source, DEM and digitizing were combined to provide anestimate of total maximum shoreline position error. The data set that was orthorectified (1937) has anestimated total maximum shoreline position error of 20.0 ft (6.1 m), while the total shoreline error for the1994, 2002, and 2009 datasets are estimated at 18.3 ft (5.6 m) for USGS and 10.2 ft (3.1 m) for VBMP. The maximum annualized error for the shoreline data is +0.4 ft/yr (+0.2 m/yr).

The Digital Shoreline Analysis System (DSAS) was used to determine the rate of change forQuantico’s shoreline (Himmelstoss, 2009). All DSAS input data must be managed within a personalgeodatabase, which includes all the baselines for Quantico and the digitized shorelines for 1937, 1996,1999, 2002, and 2009. Baselines were created about 200 feet or less, depending on features and space,seaward of the 1937 shoreline and encompassed most of the Base’s main shorelines but generally did notinclude Chopawamsic Creek. DSAS generated transects perpendicular to the baseline about 33 ft apart. ForQuantico, this method represented about 6.4 miles of shoreline along 998 transects.

The End Point Rate (EPR) is calculated by determining the distance between the oldest (1937) andmost recent shoreline (2009) in the data and dividing it by the number of years between them. This methodprovides an accurate net rate of change over the long term and is relatively easy to apply to most shorelinessince it only requires two dates. This method does not use the intervening shorelines so it may not accountfor changes in accretion or erosion rates that may occur through time. The EPR rate is shown on the Platesin Appendix A, except for Plate 2, Chopawamsic Creek. Average EPR rates were calculated along each sitesegment.

3.2 Wave Climate

Two local grids were created from bathymetry obtained from the NOAA ENC Database, one tomodel waves coming from the south and another grid to model waves coming from the northeast (Figure 3-2). In order to determine input waves, the US Army Corps of Engineers ACES(http://chl.erdc.usace.army.mil/aces) program was used to simulate waves that could occur from eachdirection exposure to the outside of the grid. The ACES application provides quick and simple estimatesfor wave growth over open-water and restricted fetches in deep and shallow water. The average fetch wascalculated to the grid edge so that wave height and period could be calculated by ACES for selected waterdepths and wind speeds.

These wave data were input to STWAVE (STeady State spectral WAVE) in order to model themaximum wave parameters at the project site. STWAVE is a half-plane model for nearshore wind-wavegrowth and propagation. It simulates depth-induced wave refraction and shoaling, current-inducedrefraction and shoaling, depth- and steepness-induced wave breaking, diffraction, parametric wave growthbecause of wind input, and wave-wave interaction and white capping that redistribute and dissipate energyin a growing wave field.

For both the south and northeast wind wave scenarios, four cases were run. The cases representconditions that may occur during a 10-yr, 25-yr, 50-yr, and 100-yr storms (Table 3-1). The 10-yr and 50-yr

storm surge elevations were reported at Chopawamsic Creek (FEMA, 1995) and referenced to the NationalGeodetic Vertical Datum 1929 (NGVD29). The elevations were converted to MLLW (1983-2001 byadding 0.44 ft to NGVD29 elevation as calculated from the National Geodetic Survey’s (NGS) benchmarksfor Colonial Beach, Virginia and Washington, DC. The 25-yr storm surge elevations were not calculated inthe FEMA (1995) report but were interpolated from the 10-yr and 50-yr storm surge levels for this analysis. While FEMA (1995) reported a 100-yr storm surge of 8.1 ft MLLW, this analysis used a storm surge of 8.6ft MLLW which was the reported stillwater level during Hurricane Isabel (September 2003) at AquiaLanding just south of Quantico (Hardaway et al., 2005).

These cases were chosen to represent the wind wave climate for design purposes. The input waveconditions enter the grid at its seaward edge (as indicated by the arrow on Figure 3-2) and are transformedacross the bathymetry of the grid to the shore. Output stations were created along the shoreline for eachindividual grid. The stations were placed at approximately 0 +0.5 ft MLW. The wave height, period anddirection were exported at each station for each wave condition.

3.3 Existing Conditions Survey and Shore Management Strategy Development

The existing conditions were determined by Shoreline Studies Program personnel in a small,shallow draft vessel, navigating at slow speeds parallel to the shoreline on 5 November 2009. Strategieswere coded into handheld global positioning system (GPS) unit, the GeoExplorer XH, and written on mapswhich were transcribed in the office. The GPS data were downloaded, processed as raw data and inGeographic Information System (GIS) to display the management strategies. Once the data were compiledand evaluated, the preferred strategies were subjected to further analysis utilizing other collected data,including existing structures, the condition of the bank face and toe, marsh width, landscape type, and GPS-referenced photos.

The shoreline was broken into 74 site segments (called both Site and Segment in the report and ongraphics) that generally have the same conditions (Appendix B). The dominant code is listed in the GISattribute table (Appendix C). However, the shoreline can include more than one type of shoreline. For the

Grid Wind Speed Surge Input Wave Input WaveDirection Year Frequency (mph) (ft MLLW) Height (ft) Period (s)South 10 10% 35 5.2 2.91 3.32South 25 4% 45 6.1 3.86 3.81South 50 2% 55 7.1 4.84 4.26South 100 1% 69 8.6 5.9 4.7

Northeast 10 10% 35 5.2 2.79 3.21Northeast 25 4% 45 6.1 3.76 3.7Northeast 50 2% 55 7.1 4.78 4.14Northeast 100 1% 69 8.6 5.87 4.56

Return IntervalTable 3-1. Wind wave conditions input to the STWAVE hydrodynamic model.

http://chl.erdc.usace.army.mil/aces

4

base of bank and bank face, shore segments were coded as erosional, transitional, or stable. Some segmentshad more than one base of bank or bank face status and were given the conditional codes of erosional andtransitional or stable and transitional. For example, an area that is coded as erosional and transitional mayhave sections of bank that are stable.

Much of the base of bank along Quantico’s main shoreline has been protected by structures(Appendix B). These structures vary considerably along the shoreline in materials and effectiveness. Somesections of the shore noted as having a protected base of bank (structure present) may have areas of erosionat the base. Overall the existing shoreline structure is protecting the base of bank, but in a few areas alongthe segment, it may not be.

The primary erosion control strategies are based on an analysis of geological, physical, andbiological factors influencing the shoreline dynamics. Future ecological impacts also are considered as wellas future threats from sea-level rise. These strategies are considered to be the optimized on-site approach.

The decision to apply a primary shore stabilization approach is based on the condition of the uplandbank at the time of the survey. Stable banks do not receive a recommendation since they either are alreadyprotected with a structure or have a sufficiently wide marsh fringe. If the shore protection is failing orinadequate then a recommendation was made.

The base of bank condition is the key. If it is erosive, undercut, scarped or slumping then thepotential exists for bank face instability. The bank condition reflects the seriousness of the problem. Whenshoreline erosion strategies are applied, the interface with the riparian edge also must be considered. If thebank face is relatively stable, the riparian edge might remain as is, but if the bank face is fully exposed andactively eroding, then bank grading might be necessary.

Geomorphic opportunities were used whenever possible to develop optimized shoreline protectionstrategies. For example, a naturally embayed shoreline between two headlands may see the structuresrecommended to protect the headlands with the intent that the shore between will stabilize. Otheropportunities include recommending additional structures, such as spurs, attached to existing structures toenhance the shoreline protection.

The recommendations generally are of types listed in Chapter 2 of this report. Cross-sections formost of the recommended structures were created. These cross-sections show the slope of the createdmarsh/beach, the size of the structure in relation to the tide range, bank interface, as well as an estimatedcost per linear foot of shoreline. The cost is an estimate of the installation cost of the rock, sand and plants. It does not include any additional work necessary such as obtaining site access, project cleanup, permitpreparation, etc.

Generally, the recommendations can be phased in. As such, each segment of shore was coded with apriority (Appendix C). Low priority has a stable bank, no threatened infrastructure, or the existing structureis adequate. Medium priority has an erosional to transitional bank or an existing failed structure. Highpriority shorelines have erosional to transitional bank with threatened upland infrastructure.

Two distinct GIS data sets were created. The first data set contains the shore segments with existingconditions. The second data set has the recommendations which can span several shore segments. As such,the information from several shore segments were visually “averaged” to best represent the existingconditions for the recommended strategy. This is particularly true of the priority. Shore segments mayhave varying priority. When a recommendation crosses several segments, other factors and data collectedwere used to determine the appropriate priority for the structure.

For ease of discussion, the Quantico shoreline has been divided into five reaches for ease ofdiscussion (Figure 3-3). Reach 1 is located along the Potomac River south of Chopawamsic Creek whileReach 2 is inside Chopawamsic Creek. Reach 3 includes the Base’s shoreline north of Chopawamsic Creekto the Town of Quantico. Reach 4 extends northward from the Town around the headland into QuanticoCreek. It ends where the bridge spans Quantico Creek. Reach 5 includes the Quantico Creek shorelinefrom the bridge to the end of the Base.

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4 Physical Setting

4.1 Geology and Shoreline Change

Along Quantico’s shoreline, the banks consist of the Patapsco Formation (Figure 4-1). The PatapscoFormation of the Potomac Group, which crops out in eastern Virginia and Maryland, contains sedimentdeposited in a large fluvial system, including stream channels, levees, crevasse splays, and meander cutoffs(Doyle and Hickey, 1976 ; Upchurch et al., 1994, Royer et al., 2010). This formation is extremely unevenand consists of variable materials, clays, sands, gravels, and conglomerates. A section of the PatapscoFormation just south of Quantico at Widewater, Virginia showed the bank to be sandy clay exposed to thewater and extending up 5-10 feet. Above that, coarse sand extended up about 15-20 feet (Clark and Miller,1912)

Much of the shoreline south of Chopawamsic Creek shows very low accretion (Appendix A-3). This likely is the result of slumping of the bank material in some areas, but also, sections of this shorelinehad sediment and/or structures placed along the shoreline over time. Much of the shoreline north ofChopawamsic Creek (Appendix A-9) shows very low erosion likely due to the influence of structuresplaced along the shoreline. Several areas show high levels erosion while others show significant fill. Pastthe bridge crossing Quantico Creek, much of the shoreline is natural. Generally, along this shore, theheadlands have higher erosion rates, sometimes more than -5 ft/yr erode while other shorelines had verylittle change (Appendix A-12).

4.2 Wave Climate

The wave climate at Quantico was modeled to determine the maximum conditions possible duringstorms. Tables 4-1 and 4-2 list the output wave heights, periods and direction for each station along theshoreline as shown in Figure 3-2. From the south, waves approach the shore at an angle. Station S5 isprotected by Chopawamsic Island and has very little impact from southerly waves (Table 4-1). Stations S1and S2 are the farthest north and also have lower southerly wave energy impacting the shore. From thenortheast during the larger storm events modeled (Table 4-2), the southernmost section of shoreline wouldbe the most impacted by larger storm waves likely due to its orientation and longer fetch.

Table 4-1. Wave conditions resulting from STWAVE modeling of the southerly wind/wave climate.

Table 4-2. Wave conditions resulting from STWAVE modeling of the northeasterly wind/wave climate.

Station Height Period Direction Height Period Direction Height Period Direction Height Period DirectionNumber (ft) (s) (Deg TN) (ft) (s) (Deg TN) (ft) (s) (Deg TN) (ft) (s) (Deg TN)

S1 1.3 3.7 319 1.8 4.3 323 2.1 4.3 323 2.8 5.6 324S2 1.9 3.7 329 2.5 4.3 335 2.9 4.3 336 3.6 5.6 337S3 2.3 3.6 335 3.1 4.3 339 3.7 4.3 338 4.3 4.3 339S4 2.2 3.6 327 3.1 4.3 332 3.9 4.3 331 4.5 4.3 333S5 1.8 3.6 340 2.6 3.6 342 3.9 4.3 341 0.9 4.3 342S6 2.1 3.6 330 2.9 3.6 331 3.9 4.3 328 4.5 4.3 331S7 2.0 3.4 331 2.9 3.6 333 3.5 4.3 331 4.6 4.3 333S8 1.7 3.4 315 2.5 3.6 320 3.2 4.3 318 4.1 4.3 322S9 1.5 3.4 316 2.2 3.6 322 3.9 4.3 320 3.6 4.3 322S10 2.0 3.4 329 2.8 3.6 332 4.0 4.3 330 4.5 4.3 332S11 2.2 3.4 336 3.0 3.6 337 4.0 4.3 334 4.6 4.3 336S12 2.3 3.4 336 3.0 3.6 337 2.9 4.3 335 4.6 4.3 337S13 1.5 3.4 318 2.0 3.6 322 2.9 4.3 320 3.3 4.3 324

10‐yr 25‐yr 50‐yr 100‐yr

Station Height Period Direction Height Period Direction Height Period Direction Height Period DirectionNumber (ft) (s) (Deg TN) (ft) (s) (Deg TN) (ft) (s) (Deg TN) (ft) (s) (Deg TN)NE1 1.1 3.3 230 1.4 3.8 231 1.9 4.3 233.3 2.4 4.8 234NE2 1.9 3.3 243 2.3 3.8 245 3.1 4.3 246.0 3.8 4.8 246NE3 1.5 3.3 260 1.8 3.8 261 2.5 4.3 261.0 3.1 4.8 260NE4 1.5 3.3 264 2.0 3.8 264 2.7 4.3 264.0 3.4 4.8 263NE5 1.4 3.3 270 1.8 3.8 270 2.4 4.3 269.0 3.0 4.8 268NE6 0.4 3.4 275 0.5 3.8 275 0.7 4.3 275.0 1.0 4.8 274NE7 1.8 3.4 250 2.3 3.8 250 3.1 4.3 252.0 3.9 4.8 251NE8 1.5 3.4 251 1.9 3.8 251 2.5 4.3 253.0 3.1 4.8 253NE9 1.3 3.4 285 1.7 3.8 282 2.3 4.3 280.0 3.0 4.8 276NE10 1.0 3.4 270 1.3 3.8 270 1.8 4.3 269.0 2.3 4.8 268NE11 1.6 3.4 250 2.0 3.8 251 2.7 4.3 250.0 3.5 4.8 250NE12 1.7 3.4 255 2.2 3.8 255 3.0 4.3 254.0 3.8 4.8 253NE13 2.1 3.4 248 2.7 3.8 248 3.7 4.3 247.0 4.7 4.8 247NE14 2.0 3.4 265 2.6 3.8 263 3.5 4.3 261.0 4.4 4.8 259NE15 2.1 3.4 253 2.7 3.8 253 3.6 4.3 251.0 4.6 4.8 250NE16 2.1 3.4 247 2.7 3.8 247 3.6 4.3 247.0 4.5 4.8 247NE17 2.1 3.4 248 2.6 3.8 248 3.4 4.3 248.0 4.4 4.8 248

100‐yr50‐yr25‐yr10‐yr

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4.3 Tide and Storm Surge

The mean tide range at Quantico is 1.40 ft and the spring range is 1.54 ft (NOAA, 2010). FEMA(1995) predicted storm surges for the Quantico shorelines are listed in Table 2. The 100-year event ispredicted to have an 8.1 ft MLLW surge. This does not include waves.

Table 4-3. Storm surge elevations at the confluence of Chopawamsic Creek and the Potomac River(FEMA, 1995).

Storm Event Frequency Elevationft NGVD29

Elevationft NAVD88*

Elevationft MLLW*’

10-yr 10% 4.8 4.0 5.2

25 yr^ 4% 4.7 4.9 6.1

50-yr 2% 6.7 5.9 7.1

100-yr 1% 7.7 6.9 8.1

500-yr 0.2% 10.6 9.8 11.0^Interpolated *Converted using NOAA datums ‘MLLW (1983-2001)

4.4 Sea-Level Rise

Sea level is rising around Chesapeake Bay. This is due to a combination of both the higher globalsea levels as well as land subsidence. Downriver from Quantico at Colonial Beach, sea-level rise has beenmeasured at 0.19 in/yr or 1.6 ft/century. Upriver of Quantico at Washington, D.C., the rate of sea-level riseis slightly less, 0.12 in/yr or 1.0 ft/century.

5 Reach 1: Potomac River South of Chopawamsic Creek

5.1 Shore Conditions

5.1.1 Reach Boundaries and Shore Change

Beginning at the mouth of Tank Creek, the base’s southern boundary, Reach 1 extends northward,upriver, for about 1.4 miles to Chopawamsic Creek (Figure 5-1 and Figure 5-2). The reach is divided intotwo subreaches, 1A and 1B, and consists of 24 shore segments based on shore type. Reach1A is mostlywooded, un-managed upland while Reach 1B is a developed upland coast with base infrastructure, roadsand buildings near the shore. Reach 1A is about 0.9 miles in length and includes shore Segments 1 to13. Reach 1B includes shore Segments 14 to 24 and is about 0.4 miles in length.

Historic shore change along Reach 1 is slightly variable ranging from -0.39 to 1.36. Some of theshore advance appears to be more a function of slight beach accretion often caught by fallen trees. In thiscase, the measure of MLW over time often does not reflect the condition or change in upland bankconditions. In the case of Reach 1A, the upland bank has obvious erosion as evidenced by verticallyexposed bank face along much of the coast. The top of upland banks, especially when heavily wooded, aredifficult to delineate in older aerial imagery. Reach 1B is heavily influenced by the upland development ofthe MCB, Quantico where riverward filling was common and positive shore changes are calculated.

5.1.2 Upland and Shore Characteristics

Reach1A shoreline starts at Tank Creek as a low bank headland in Segment 1 (Figure 5-3A). Theupland banks rise up and are between 10 feet and 30 feet MLW along the length of the Reach. The base ofbank and bank face area intermittently undercut and eroding with no coastal protection structures present(Figure 5-3B, Figure 5-3C). A relatively wide beach face exists along the Reach, but the backshore width isless the 10 feet along most of the reach (Appendix B-1). Numerous fallen trees occur along the shore(Figure 5-3D). Indurated bank rock that is moderately resistant to erosion and weathering is exposed alongSegments 4, 5, 6, and 7 of the Reach (Figure 5-3E). The railroad line comes very close to the eroding bankat Segments 4 and 5 making these critical areas of concern (Appendix B-1).

Reach 1B begins where the base upland infrastructure begins (Segment 14) and extends to the mouthof Chopawamsic Creek (Segment 24) (Appendix B-1). The bank reaches heights of up to 20 feet MLW, butalso has sections with only a minimal bank. Reach 1B begins where the upland has been developed withvarious base infrastructure including buildings, concrete pads and parking lots (Figure 5-3F, Figure 5-3G). The shoreline has been protected for the most part with stone revetment, old concrete walls and old stonewalls (Figure 5-3H), but the bank generally still erosional. These structures also have reduced the intertidalbeach width and backshore along most of the reach. At the mouth of Chopawamsic Creek (Segment 24),the bank is about +20 ft MLW and erosional even though the base has been protected by rock and rubble(Figure 5-3I)

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5.1.3 Nearshore Characteristics

The nearshore width along Reach 1, from MLW to the -6 ft contour, varies from about 1,600 feet offTank Creek to about 600 ft off Segment 9 and continues so to the entrance of Chopawamsic Creek. Thelandward limit of SAV averages about 25 feet from MLW and consists of various species includingcoontail, water stargrass, hydrilla, Eurasian watermilfoil, southern naid, and wild celery.

5.2 Design Considerations and Recommendations

The No Action alternative along Reach 1 would allow erosion of upland banks of Quantico’sproperty to continue to intermittently erode. Several areas of Reach 1 should be considered for furtheraction. These include shore Segments 2 through 7, due to the proximity of the railroad tracks to theshoreline. The top of the eroding bank is less than 10 ft from the railway ballast stone foundation. Becausethe railroad tracks curve, this is the only area where the tracks are threatened.

The inner limit of SAV is relatively close to the shore at Segments 1 through 7 and makes a largesill or breakwater system problematic from a permitting perspective so in general, a revetment isrecommended. The design consideration for Segment 5, where the railroad bed is most threatened, is toprovide shore protection for the 100-year storm as defined in Figure 5-4A. The revetment would continueup and down river. Downriver, the revetment could drop as the bank got lower and the railroad turnswestward (Figure 5-4B). The upriver extension should be built to a “safe” distance from the railroad thendrop down where the option could be to transition to a sill (Figure 5-4C). Here, three sill segments acrossexisting small beach headlands and/or revetments are proposed along Segments 8 and 9. A continuous sillwould then begin at Segment 10 (Figure 5-1). The proposed sills have to stay close to shore to avoid SAV,but this is possible because the backshore widens upriver and the back face is less erosive making thesituation less critical. This would provide shore protection to something less than the 100-year storm, morein line with the 25-year event.

The sill continues to Segment 11 where no structure is proposed for about 400 feet because anupland drainage crosses the shore (Figure 5-1). The backshore is wide while the banks are low and noterosive. Also, the nearshore bottom might be soft and may not adequately support a structure. The sillbegins again on Segment 12 and continues upriver where it is intermittently gapped at a small embaymentalong the coast (Figure 5-1).

Reach 1B begins at the boundary of Segment 13 and Segment 14 where upland and shorelinedevelopment begins (Figure 5-2). The groin-type existing structure at the boundary between Segments 14and 15 has created a headland/geomorphic opportunity. The existing beach can be enhanced with spurs anda breakwater with a beach fill along this section of shore. These structures also will provide added scourprotection to the low upland that is now protected by a revetment and low wall (Figure 5-2).

Along shore Segment 16 the bank rises to about + 15 feet MLW and continues across Segment 17. The bank face is intermittently transitional to exposed and eroding along the top which is within a few feetof adjacent parking lots on Segment 16. The base of bank is erosional to transitional. If not for the

proximity of the parking lots to the top of the bank, a sill would be appropriate and recommended forSegment 17. However, to insure bank protection on Segment 16 a revetment is the preferred strategy(Figure 5-5A).

The upland bank drops down to + 8 MLW beginning at Segment 18 where a sloping concrete walloccurs. Although in fair condition, the wall is old and signs of deterioration are evident along its base. “DoNothing” is an option, but a low sill would soften the hard edge and provide scour protection the base. AtSegment 19 the bank drops to about +5 ft MLW and the shore is protected with low stone and concretewalls which are old and could benefit from armoring the face with rock or a low sill system (Figure 5-5B).

The upland bank rises to about + 10 along Segment 20 where the base of bank is undercut anderosive. A sill is proposed (Figure 5-5C). In Segment 21, a low stone wall protects a stable upland bankface. Again the wall is old but still in fair conditions. “Do Nothing” is an option or the sill could beextended. Along shore Segment 22, a crib wall appears to be in good condition and is protecting the bank. Along shore Segment 23, the base of bank is transitional with a transitional to stable, but steep, top of bank. However, about midway alongshore, the upland bank, now about + 20 feet MLW, has a parking lot near thetop of the bank. Here a sill or revetment is proposed (Figure 5-5D). A revetment might require excavatingthe bank slump, and a more detailed geotechnical analysis is recommended.

Segment 24 is on the headland point at the confluence of Chopawamsic Creek and the PotomacRiver. Broken concrete along the base of the bank offers minimal shore protection. The bank face is steepand heavily vegetated. A sill or revetment should be installed to hold this point and protect the nearbyparking lot at the top. However, as this area begins to come into view of the runway and aircraft operations,a revetment might be preferable to the sill with the marsh habitat component. This also is the end of Reach1 and the beginning of Reach 2.

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6 Reach 2: Chopawamsic Creek



Reach 2 includes 6.4 miles of Chopawamsic Creek, but most of the shoreline managementrecommendations occur along the long narrow entrance channel that extends about 1,800 feet from thePotomac River and averages about 125 feet wide (Figure 6-1). The remaining shoreline aroundChopawamsic Creek was visited but not assessed in detail because it is all wooded or marsh coast with nothreatened infrastructure, and erosion rates are very low. Base personnel placed those shorelines as lowpriority. The Reach is divided into three subreaches. Reach 2A extends along the south side of the entrancechannel and Reach 2C along the north. Reach 2A includes Segments 24 to 28 and Reach 2C has Segments29 to part of 32. Reach 2B is the remaining shoreline around Chopawamsic Creek, about 5.8 miles.

The channel into Chopawamsic has been in its present configuration at least since the 1930s and hasshown little change over time at the scale of the shore change analysis. While historic shoreline change isminimal, bank erosion threatens the upland infrastructure along the length of Reach 2A. Erosion continuesalong the low bank inside Chopawamsic Creek beyond the boat ramp. The northern side of the channel,Reach 2C, has been hardened from the entrance to just past the railroad and Base road overpass bridgeswhere the low bank continues to erode.

The shoreline inside the creek, Reach 2B, has obvious erosional sections of shore, but they were notcalculated for this report. However, the historic and recent shorelines were digitized and are shown inAppendix A, Plate 2. Rates of change can be approximated by scaling change and dividing by the numberof years between the shores.

6.1.2 Upland and Shore zone Characteristics

The bank height along Reach 2A is about +20 ft MLW. The base of bank is either undercut orerosional along Segments 24 and 25 with a transitional to stable bank face (Figure 6-2A). One problem isthat occasional slumping occurs and threatens the parking lot. Efforts to fix this are seen in Segment 26with a rock toe and concrete bank face (Figure 6-2B). Shore Segment 27 is fairly stable to the bridge wherethe abutments act as a tall bulkhead along the shore (Figure 6-2C). Beyond the bridges, the low bank ismostly undercut and erosional, Segment 28 (Figure 6-2D).

The Reach 2B coast along the interior of Chopawamsic Creek has mostly high wooded banks on thesouth shore that are intermittently undercut (Figure 6-2E and Figure 6-2F) and eroding on the headlandswith stable bank faces. Wide marsh complexes and narrow marsh fringes also occur. The north coast islower in elevation with broad marsh complexes along much of its shore (Figure 6-2G).

Reach 2C begins on the north side of the entrance channel in Chopawamsic Creek as a low bank onSegments 29 and 30 (Figure 6-2H). Riverward of the bridge, the bank becomes higher and the shoreline

bridge abutment is bolstered by gabions (Figure 6-2I). For the remainder of Reach2C, Segment 31 has beenarmored with stone (Figure 6-2J) and part of Segment 32 has scattered broken concrete alongshore andintermittently eroding upland banks (Figure 6-2K).

6.1.3 Nearshore characteristics

The narrow entrance channel into Chopawamsic Creek (Reach 2A and 2C) is straight and about 125feet wide at MHW. It averages about 3 to 5 feet deep in the center. No SAV occurs along the bottom. Thechannel widens quickly into Chopawamsic Creek which is a wide but very shallow water body. Historicalimagery in 1937 of Chopawamsic Creek (Appendix A-4) shows a series of interior channels that appear tobe through tidal marsh and abundant SAV. Today, the channels are less defined, and SAV is still abundant.


For Reach 2A, the “Do Nothing” option requires careful monitoring of the high upland bank face forsigns of continued slumping and bank undercutting. A proactive approach would involve a more detailedsurvey of the upland bank and a geotechnical investigation to better understand the short and long-termstability of the bank face. Long-term stabilization could be done with a free standing revetment and bankgrading (Figure 6-3A). Inside the creek, if left alone, the low bank would continue its slow erosion process. Alternatively, a low revetment could be installed (Figure 6-3B) that transitions to a sill past the boat ramp(Figure 6-3C).

The Reach 2B coast has been determined by Navy personnel to be logistically too difficult toaddress the several small erosive headlands that exist. Access to the site by land would require clearingwoods and it’s too shallow to get in by water even if one could get under and through the bridge.

For Reach 2C the low banks on the north shore would continue to erode at a slow rate if nothing isdone. Alternatively, the lower banks could use a low sill (Figure 6-3C) and the higher banks with arevetment (Figure 6-3B). The riverward section of Reach 2C, Segment 31, has been protected with riprapboth new (Figure 6-2J) and old (Figure 6-2I). At the beginning of Segment 32, old broken concrete isdeteriorating and does not offer proper shore protection (Figure 6-2K) as evidenced by continued bankerosion. “Rearmoring” the bank with stone would provide for long term-shore protection (Figure 6-3D).

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7 Reach 3: North of Chopawamsic Creek to the Marina



Reach 3 extends from the mouth of Chopawamsic Creek upriver for about 2.5 miles to the Basemarina. It is subdivided into four shore segments. Reach 3A extends to north end of runway 02 andincludes Segments 32, 33 (Figure 6-1), 34, 35 and 36 (Figure 7-1) and is about 1.1 miles long. This longstretch of shoreline is adjacent to aircraft operations. Reach 3B extends upriver for about 2,300 feet andincludes Segments 37 and 38 (Figure 7-1). Reach 3C is relatively short at 1,400 ft and includes Segments39, 40, 41, 42, 43 and 44 (Figure 7-2). The next reach, 3D includes shore Segments 45, 46, 47, and 48(Figure 7-2) and is about 3,400 feet in length and ends at the Base marina.

The 1937 aerial imagery shows the base in early stages of development. The outline of Runway 02can be seen (Appendix A-1). Since then, historic shore change has been a function of shoreline hardeningalong Segments 32 and 33. Significant erosion has occurred in Segments 34, 35 and 36 (Appendix A-9). Conversely significant accretion occurred in Segments 37 and 38 (Appendix A-9) likely as a result ofplacement of material along the shore. Shore retreat dominates the rest of Reach 3C and 3D, which hasmostly hardened, except for the shore advance near the marina, Segments 46 and 47, where filling hasoccurred (Appendix A-9).

The shoreline turns into an embayment between shore Segments 33 and 44 and is partially protectedfrom the impinging wind/wave climate by Chopawamsic Island. This section of shore will be called“Chopawamsic Bay” for purposes of discussion in this report.

7.1.2 Upland and Shore Zone Characteristics

The Reach 3 shoreline has mostly been hardened or otherwise modified over time by filling. Reach3A has been protected by various materials mostly broken concrete and rock. The bank height is fairlyconstant at about +10 ft MLW along most of Segment 32. A runway intersects the shore about half wayalong Segment 32 (Figure 7-3A). The broken concrete used along the upland bank is randomly-placed andoccasionally intermixed with rock (Figure 7-3B) but functioning as shore protection nevertheless. However, it is not an engineered structure and there are many voids and inconsistencies.

At the boundary between Segment 32 and 33, the upland bank is characterized with mostly rockalong the base, broken concrete along top with a grassy swath in between (Figure 7-3C). An LCAC landingramp is the approximate boundary between Segments 33 and 34 and consists of a series of parallel concretebeans on grade (Figure 7-3D). The bank elevation drops to about +5 ft MLW to the end of Reach 3A,Segments 34, 35 and 36 where a broken concrete and unprotected erosional low banks (Figures 7-3E and 7-3F).

Reach 3B includes Segment 37, a low unprotected marshy shoreline that is eroding (Figure 7-3G)and Segment 38 which has been armored with a stone revetment (Figure 7-3H). Reach 3C is a low erodingmarshy shoreline (Figure 7-3I) with a small stone wall (Figure 7-3J) on Segments 39 and 40. Segment 41 isvery low with scattered pieces of broken concrete (Figure 7-3K). The bank rises to more than 10 feet onSegment 42 with a small beach and relatively wide backshore (Figure 7-3L). More broken concrete occursalong the base of the upland banks in Segments 43 and 44. The bank face is relatively stable withvegetation but steep with leaning trees, evidence of slow bank creep (Figure 7-3M).

Reach 3D begins with a concrete/stone wall on Segment 45 (Figure 7-3O) which continues for about2,400 feet. The wall is in fair to good condition (Figure 7-3P) along most of its length. There is a Baselandmark, the Wisdom Tree, which is perched on the bank (Figure 7-3N). Numerous weep holes helprelieve hydrostatic pressure from upland runoff and groundwater. The wall ends and Segment 46 where avery low bank (Figure 7-3Q) and small embayment begins. Broken concrete along the shore continuesacross Segment 47 (Figure 7-3R) to the marina. The marina shore is protected by a bulkhead, and the docksare protected from wave action by a concrete wall (Figure 7-3S) on the south and large dock on the north,Segment 48 (Figure 7-3T). The marina marks the end of Reach 3.


The -6 foot contour is relatively close to shore along Segment 32 averaging about 300 feet fromMLW. The nearshore shelf gets wider in Chopawamsic Bay in the shelter of Chopawamsic Island where itaverages more than 1,000 ft offshore. The -6 contour draws within 300 feet by the end of Reach 3D. SAVremains very close to shore along the entirety of Reach 3.


The no-action alternative for Reach 3A would not result in short-term problems for the existingshore protection. While the existing materials have been functioning to protect the bank, long-term localfailures in the broken concrete layers will lead to bank slumping. This can be addressed by adding morebroken concrete or stone. The use of a Living Shoreline approach is not feasible because the createdwetlands may pose a BASH issue by attracting waterfowl.

The long-term option for Segment 32 and 33 would be to rework the existing broken concrete andadd armor stone as discussed in previous section (Figure 6-3D). This would provide predictable protectionfor the exposed airfield coast that would be designed to withstand a 100-year storm.

As the shoreline turns into “Chopawamsic Bay,” the bank becomes lower and there is much lessbroken concrete. Continued slow erosion of the upland can be expected. A coarse cobble beach could becreated to protect the low eroding upland bank rather than hardening the shore with a stone revetment. Thisis proposed for Segments 34, 35 and 36 (Figure 7-4A).

10

Reach 3B includes shore Segments 37and 38, both of which are the result of infilling. Segment 37 isa low marshy shoreline with a very soft bottom. A “Do Nothing” approach is recommended. Segment 38has been recently protected by a stone revetment (Figure 7-3U).

A “Do Nothing” approach would not result in any significant shoreline retreat along Reach 3Cbecause of the intermittent presence of broken concrete. However, this shore provides the opportunity tobuild “Living Shoreline” marsh sills. This is recommended for Segments 40 and 41 which have a low bank (Figure 7-4B) and Segments 42, 43 and 44 which have high banks (Figure 7-4C).

Most of Reach 3D is protected by a concrete wall that appears to be in good condition. In this case a“Do Nothing” approach may be warranted. However, a more detailed analysis should be performed toensure the long-term integrity of the wall. Problems such as scour along the base can be addressed by usingstone along the front face. Large trees along the adjacent bank face might pose a bank stability problem ifuprooted and dislodged during large storms. This might be a problem with the large oak on the riverbankby the Wisdom Tree. If it were to be blown down then the large root system would pull out a large portionof the bank, which could in turn threaten the bank by the Wisdom Tree.

A spur and some sand fill along the upriver end of Reach 3D will help maintain the smallembayment on Segment 46. The remaining coast, Segment 47, could be left alone as broken concreteoccurs along the shore or it could be armored for long-term integrity (Figure 7-4D).

8 Reach 4: North of the Marina to Quantico Creek



Reach 4 extends from the marina upriver for about 1 mile around Shipping Point and into the mouthof Quantico Creek (Figure 8-1 and Figure 7-2). It includes shore Segments 49 through 56 (Appendix B-2). Segment 49 is the park in the Town of Quantico and is labeled Reach 4A. Reach 4B extends from the Townpark north around Shipping Point and includes shore Segments 50 through 54. The Reach 4C coastcontinues alongshore to the Railroad Avenue bridge that crosses Quantico Creek.

Historic shore change shows shore advance from filling adjacent to the marina wall in Reach 4A andas well as in the tidal creek channel. Little net change along the beginning of Reach 4B, Segment 50, is dueto shore hardening. Shore advance due to beach accretion occurs toward the north half of Segment 50. Moderate shore retreat occurs in Segments 51, 52 and 53 along the Potomac River to Shipping Point. Historic shore retreat occurs along the Quantico Creek shore along Segments 54 and 55 to the boat rampexcept for an area of filling just east of the ramp. A cut and fill sequence occurs around the next point alongSegment 56 where marsh accretion occurs.

8.1.2 Upland and Shore Zone Characteristics

A small tidal creek at the upriver boundary of the Town’s park can be seen in 1937 imagery(Appendix A-7). However subsequent images show that the creek was dammed resulting in accretion of theshore. The bank is low with a narrow beach with grassy backshore (Figure 8-2A). A low stone wall (Figure8-2B) transitions to a small beach and then broken concrete which is protecting the fill at the old creekchannel (Figure 8-2C). The north end of the wall has failed allowing some bank scarping (Figure 8-2D).

A concrete wall starts at Reach 4B, Segment 50, which is similar to the type and style seen in Reach3D (Figure 8-2E). The upland bank along this shore is heavily vegetated and stable. No backshore/beachexists along the first half of Segment 50, but farther north, the sandy backshore increases in width to about30 feet at the Segment 50/51 boundary where the concrete wall ends. Segment 51 is a low bank and iswhere there once was a series of wharfs as seen in 1937 imagery (Appendix A-7)and whose remains areseen in Figure 8-2F. These likely are the remnants of Quantico Shipyards which was established in theearly 1900s. Some scattered broken concrete is concentrated alongshore and intermittent bank scarpingoccurs. The piles of concrete have created small headland features.

This trend continues around to Segment 52 (Figure 8-2G) as the bank rises to about +15 feet MLW. The concrete wall begins again at Segment 53 (Figure 8-2H). The upland bank is heavily vegetated andstable, and no beach exists. The wall continues to and around the next point of land and ends where an oldbulkhead begins (Figure 8-2I).

11

Reach 4C begins with Segment 54 which is short and has an old wood bulkhead with horizontal“sheets”. The upland bank is stable and there is no beach (Figure 8-2J). Segment 55 has a low undercutupland bank that has a gradual to steep bank face and vegetated. A few scattered rocks and pieces of brokenconcrete occur along the shoreline, but no structurally-sound shore protection structures occur (Figure 8-2K). A narrow beach face is exposed at low water to the small boat ramp (Figure 8-2L). The ramp marksthe end of Segment 55 and the beginning of Segment 56, which is a very low, slightly undercut bank withan intermittent marsh fringe that continues around into the mouth of Quantico Creek.


The - 6 ft contour, except for Segment 49, is within 100 feet of the shoreline around the Reach 4coast. SAV beds remain close to shore.


Reach 4A, the waterfront park for the Town of Quantico, currently has a stable beach area but theold stone wall is failing with some consequent bank scarping. For a park, the failing wall and brokenconcrete at the north end seem a bit unsightly. To enhance the beach and provide some a living shorelinecomponent, the recommended shore strategy would be the addition of sand, a small sill along the wall, and aspur at the north and south end. The spur would transition into a sill and spur on the north headland.

The concrete wall along Reach 4B, Segment 50, is in good shape so a “Do Nothing” approach isrecommended. The north boundary of Segment 50 with Segment 51 and including Segments 52 and 53, theexisting broken concrete headlands offer a geomorphic opportunity to utilized headland breakwaters andbeach fill to create stable pocket beaches for shore protection (Figure 8-3A).

Around Shipping Point where the banks are undercut, Segment 55, a sill system would provideshoreline and base of bank protection (Figure 8-3B). Further along beyond the boat ramp, Segment 56, theupper intertidal zone could benefit is the intertidal marsh was planted along its eroding marsh edge (Figure8-3C). A very low sill could be added for long-term integrity.

9 Reach 5: Quantico Creek

Reach 5 includes the shoreline of Quantico Creek inland of the railroad bridge, approximately 1.8miles (Appendix B-2). This reach contains Segments 57 through 74. Much of this shoreline has had verylittle shoreline change, either very low erosion or very low accretion (Appendix A-12). Several sections ofshoreline, particularly near the points of land at Segments 60 and 72, have had medium and high erosion. Asection of shoreline, just west of the railroad bridge, Segment 57, shows long-term accretion. It is likelythis is the result of infill since 1937 (Appendix A-10), but the historical images are not conclusive. However, Phragmites Australis is growing in the marsh indicating fill material. The bank along this Reachvaries between erosional and stable (Figure 9-1 and 9-2) mainly due to the undulating topography that hassome sections of banks vertically-exposed along the shoreline while others have a gradual slope from thewater to the top of bank.

This shoreline is low and marshy adjacent to the railroad bridge at Segment 57(Figure 9-3A). Thebank rises farther up Quantico Creek at Segment 58 where the bank face is relatively stable, but the base ofthe bank has minor scarping (Figure 9-3B). One section of bank at the boundary between Segments 58 and59, has been cleared and tiered from the top of the bank near the building and parking lot to the water line(Figure 9-3C). However, minor base of bank scarping continues. Segment 59 has a section of vertically-exposed, eroding bank (Figure 9-3D). Segment 60 is a point of low, eroding marsh (Figure 9-3E). Thispattern of vertically-exposed, eroding banks and gradual slope banks continues up Quantico Creek (Figure9-3F) except where a marsh drainage enters the Creek between Segments 68 and 69 (Figure 9-3G).

The nearshore is very shallow in Quantico Creek. There is no -6 ft contour within the Creek. Inaddition, SAV is very dense close to the shore (Figures 9-3H and 9-3I).

Even though some sections of the shoreline have vertically-exposed banks and are eroding, nostructures have been recommended for this Reach. Most of this Reach is wooded with no infrastructure. Assuch, no access to the shoreline is readily available. In addition, the density of the SAV in the Creek willmake it difficult to access by water and construct a structure. Just north of the railroad bridge at Segment58, infrastructure is located close to the top of bank. A sill (Figure 7-4B or 7-4C) could be installed alongthe eroding bank.

12

10 Summary and Cost of Structures

The Quantico Shoreline Protection Plan was developed at the request of MCB, Quantico to provide a document for making decisions along the Base shoreline regarding the nature of shore change and how it impactsupland infrastructure. The location and functionality of existing structures as well as physical parameters of the shore zone were used to make shore management recommendations. Overall, 34 structures were recommendedalong 16,844 feet of shoreline (Table 10-1). Eight individual breakwater units were recommended as were revetments, sills, and spurs. Two sections of existing revetment was recommended for rehabilitation. A cobblebeach was recommended along 2,100 feet of shoreline. In addition, 1,200 ft of beaches will be constructed in conjunction with the breakwaters ad spurs.

An estimated cost of the installation cost of the rock, sand and plants was calculated and summarized by Reach and by priority (Table 10-1). Costs are conceptual estimates based on recommended structure cross-sections. It does not include any additional work necessary such as obtaining site access, project cleanup, permit preparation, etc. A recent survey and updated design is needed to determine actual costs. Amount of cut/fillfrom the bank was difficult to determine and is an estimate only. Since the recommendations can be built in phases, a structure priority also is noted. Low priority recommendations have a stable bank, no threatenedinfrastructure, or the existing structure is adequate. Medium priority recommendations have an erosional to transitional bank or an existing failed structure. High priority shorelines have erosional to transitional bank withthreatened upland infrastructure. Tables 10-2 through 10-5 show the materials and estimated costs of individual recommended structures for each reach. It should be noted that the individual shoreline sites were given apriority (as shown in Appendix C), and when the recommended structure crossed several sites, the priority listed in the following tables are based on a visual “average”. For instance, the recommended Cobble Beach 3A-1includes Sites 34, 35, and 36. Sites 34 and 35 have medium priorities because the airstrip is not in close proximity to the shoreline. However, Site 36 is given a high priority because a section of the airstrip is close to theshoreline. When creating a priority ranking for the recommended structures, the individual site priorities were taken into account as was other data. In the case of Cobble Beach 3A-1, because the section of shore in questionis behind Chopawamsic Island, it was determined that in the context of the overall shoreline management plan, this structure would have a medium priority rather than high. Other structures may have similar situations.

Table 10-1. Summary of recommended structures for Quantico’s shoreline with estimated costs by Reach and by priority. Costs are conceptual estimates based on recommended structure cross-sections.

Type TotalNum.

Total Length(ft)

Total Cost by Reach Total Cost by Priority

Breakwater 8 845 Reach 1, Revet Option 1 $2,790,020 High Priority $1,699,500Revetment 7 4,224 Reach 1, Sill Option 2 $2,710,080 Medium Priority

Revetment Rehab 2 3,960 Reach 2 $776,420 With Option 1 $4,842,240Revetment or Sill 1 370 Reach 3 $2,550,940 With Option 2 $4,762,300

Cobble Beach 1 2,112 Reach 4 $519,320 Low Priority $94,960Sill 13 5,227 Total with Option 1 $6,636,700Spur 2 106 Total with Option 2 $6,556,760Total 34 16,844

13

Table 10-2. Material and cost estimate summary for Reach 1. Costs are conceptual estimates based on recommended structure cross-sections. A recent survey and updated design is needed to determine actual costs.


Structure Reach Number Priority Length Rocks Sand Plants Bank Grade* Rock Sand Plants Bank Grade Structure Type Cut/Fill Total

(ft) (tons/ft) (cy/ft) (plants/ft) (cy/ft) ($) ($) ($) ($) ($)Revetment 1A 1 H 1850 6 5 $888,000 $92,500 $980,500

Revetment (Option1) 1A 2 M 550 6 5 $264,000 $27,500 $291,500Sill (Option 2) 1A 1 M 200 4.5 2.8 22 $72,000 $22,400 $8,800 $103,200Sill (Option 2) 1A 2 M 80 4.5 2.8 22 $28,800 $8,960 $3,520 $41,280Sill (Option 2) 1A 3 M 130 4.5 2.8 22 $46,800 $14,560 $5,720 $67,080

Sill 1A 4 M 530 4.5 2.8 22 $190,800 $59,360 $23,320 $273,480Sill 1A 5 M 300 4.5 2.8 22 $108,000 $33,600 $13,200 $154,800Sill 1A 6 M 470 4.5 2.8 22 $169,200 $52,640 $20,680 $242,520

Beach 1B 1 L 100 4.5 3 10 $36,000 $12,000 $2,000 $50,000Breakwater 1B 1 M 90 5 3 10 $36,000 $10,800 $1,800 $48,600

Sill 1B 1 H 750 4 2 18 $240,000 $60,000 $27,000 $327,000Sill 1B 2 M 400 4 2 18 $128,000 $32,000 $14,400 $174,400Sill 1B 3 M 270 4 2 18 $86,400 $21,600 $9,720 $117,720

Revetment 1B 1 H 350 4 5 $112,000 $17,500 $129,500Total with Revetment 1A-2 $2,790,020

Total with Sills 1A-1, 2, and 3 $2,710,080

Structure Reach Number Priority Length Rocks Sand Plants Bank Grade Rock Sand Plants Bank Grade Structure Type (ft) (tons/ft) (cy/ft) (plants/ft) (cy/ft) ($) ($) ($) ($) Total

Revetment 2A 1 H 400 4 3 $128,000 $12,000 $140,000Revetment 2A 2 H 350 4 3 $112,000 $10,500 $122,500Revetment 2A 3 M 500 2.5 $100,000 $100,000

Sill 2A 1 L 120 1.5 1 8 $14,400 $4,800 $1,920 $21,120Sill 2C 1 M 200 1.5 1 8 $24,000 $8,000 $3,200 $35,200

Revetment 2C 1 M 380 2.5 $76,000 $76,000Revetment 2C 2 M 440 8 $281,600 $281,600

Total $776,420

14



Table 10-6. Summary of cost estimate by reach. Costs are conceptual estimates based on recommended structure cross-sections. A recent survey and updated design is needed to determine actual costs.

Structure Reach Number Priority Length Rocks Sand Plants Bank Grade Rock Sand Plants Bank Grade Structure Type (ft) (tons/ft) (cy/ft) (plants/ft) (cy/ft) ($) ($) ($) ($) Total

Revetment 3A 1 M 2800 8 $1,792,000 $1,792,000Cobble Beach 3A 1 M 2100 2.5 $420,000 $420,000

Sill 3C 1 M 850 2.5 1.6 11 $170,000 $54,400 $18,700 $243,100Spur 3D 1 L 60 2.5 1.6 $12,000 $3,840 $15,840

Beach 3D 1 L 100 2 $8,000 $8,000Revetment 3D 1 M 300 3 $72,000 $72,000

Total $2,550,940

Structure Reach Number Priority Length Rocks Sand Plants Bank Grade Rock Sand Plants Bank Grade Structure Type (ft) (tons/ft) (cy/ft) (plants/ft) (cy/ft) ($) ($) ($) ($) TotalSpur 4A 1 M 50 2.5 1.6 8 $10,000 $3,200 $800 $14,000

Breakwater 4A 1 M 130 2.5 1.6 8 $26,000 $8,320 $2,080 $36,400Breakwater 4A 2 M 110 2.5 1.6 8 $22,000 $7,040 $1,760 $30,800Breakwater 4A 3 M 110 2.5 1.6 8 $22,000 $7,040 $1,760 $30,800Breakwater 4B 1 M 110 3.5 3 18 $30,800 $13,200 $3,960 $47,960

Beach 4B 1 M 110 2 12 $8,800 $2,640 $11,440Breakwater 4B 2 M 70 3.5 3 18 $19,600 $8,400 $2,520 $30,520



Sill 4C 1 M 750 2.5 1.5 13 $150,000 $45,000 $19,500 $214,500Total $519,320

Reach 1, Revetment Option1 $2,790,020Reach 1, Sill Option2 $2,710,080Reach 2 $776,420Reach 3 $2,550,940Reach 4 $519,320

Total with Reach 1 Revet $6,636,700Total with Reach 1 Sill $6,556,760

15

11 References

Clark, W.B. and B.L. Miller, 1912. The Physiography and Geology of the Coastal Plain Province ofVirginia. Bulletin No. IV, Virginia Geological Survey, University of Virginia, Charlottesville,Virginia.

Doyle , J. A. , and L. J. Hickey . 1976 . Pollen and leaves from the mid-Cretaceous Potomac Group andtheir bearing on early angiosperm evolution. In C. B. Beck [ed.], Origin and early evolution ofangiosperms, 139 – 206. Columbia University Press, New York, New York, USA.

FEMA, 1995. Flood Insurance Study, Prince William County, Virginia and Incorporated Areas. FederalEmergency Management Agency.

Hardaway, C.S., Jr. and R.J. Byrne, 1999. Shoreline Management in Chesapeake Bay. College of William& Mary, Virginia Institute of Marine Science, Gloucester Point, VA 54 pp.

Himmelstoss, E.A. 2009. “DSAS 4.0 Installation Instructions and User Guide” in: Thieler, E.R.,Himmelstoss, E.A., Zichichi, J.L., and Ergul, Ayhan. 2009 Digital Shoreline Analysis System(DSAS) version 4.0 — An ArcGIS extension for calculating shoreline change: U.S. GeologicalSurvey Open-File Report 2008-1278.

Morton, R.A., T.L. Miller, and L.J. Moore. 2004. National Assessment of Shoreline Change: Part 1Historical Shoreline Change and Associated Coastal Land Loss along the U.S. Gulf of Mexico. U.S.Department of the Interior, U.S. Geological Survey Open-File Report 2004-1043, 45 p.

National Oceanic and Atmospheric Administration. 2010. Tides and Currents.http://tidesandcurrents.noaa.gov/

National Spatial Data Infrastructure. 1998. Geospatial Positional Accuracy Standards, Part 3: NationalStandard for Spatial Data Accuracy. Subcommittee for Base Cartographic Data. Federal GeographicData Committee. Reston, VA.

Royer, D.L., I. M.. Miller, D. J. Peppe, and L. J. Hickey, 2010. Leaf Economic Traits from Fossils Supporta Weedy Habit for Early Angiosperms. American Journal of Botany 97(3): 438–445.

SAV, 2007. Submerged Aquatic Vegetation Report 2007. http://web.vims.edu/bio/sav/sav07/index.html

Upchurch , G. R. , P. R. Crane , and A. N. Drinnan . 1994 . The megaflora from the Quantico locality(Upper Albian), Lower Cretaceous Potomac Group of Virginia. Virginia Museum of Natural HistoryMemoir 4 : 1 – 57 .

http://tidesandcurrents.noaa.gov/

http://web.vims.edu/bio/sav/sav07/index.html

Figure 1-2. Boundaries of MCB, Quantico and the Town of Quantico.

ColonialBeach

Aquia Landing

Marine CorpsBase,Quantico

Figure 1-1. Location of Marine Corps Base, Quantico within the Chesapeake Bay estuarine system. 16

Figure 2-1. Sand fill with stone sills and marsh plantings at Webster Field Annex, St.Mary’s County, Maryland A) before installation, B) after installation but beforeplanting, C) after four years, and D) the cross-section used for construction.

28 Mar 2003

19 Jun 2007

A

B

C

PlantS. alterniflora

PlantSpartina patens

ExistingGround

Armorstone

Filter fabric

3 ft+0.8 ft

Proposed sill

1.5ft

+2.5 ft

Corestone

Proposedsand fill

Spartinaalterniflora

Spartinapatens

D

Spartina patens

Beach Nourishment

Breakwater

MHW

MLW

Spartina alterniflora30

20

10

0

Ele

va

tio

n(f

ee

t)

Figure 2-2. Breakwater system on Patuxent River in Calvert County, Maryland and a

typical breakwater cross-section.

A

B

17

Figure 2-3. A) Stone revetment shortly after construction on the Potomac River, Virginia, and B) cross-section of the elements necessary for proper stone revetment design (Hardaway and Byrne, 1999).

B30

20

10

0

EL

EV

AT

ION

(feet) BANK BEFORE CONSTRUCTION

ARMOR STONE SPLASHAPRON

GRADEDBANK

TOEAPRON

MHWFILTER CLOTH

BEDDING STONE

12

0 10 20 Feet

MLW

CRESTELEVATION

A

DetachedBreakwaters

Rev

etm

ent

Spur

Spur

Spur

Revetment

Figure 2-4. Shore-attached and structure-attached spurs used as part of a shore protection system at PointLookout, Maryland. Photo date 12 Jan 2006.

18

Figure 2-5. Location and density of submerged aquatic vegetation at MCB, Quantico as mapped by theVirginia Institute of Marine Science in 2009 (http://web.vims.edu/bio/sav/maps.html).

Figure 3-1. Index of plates used to display historical and recent aerial imagery and the rates of shorelinechange. 19

Grid 1 Directionof Wave Input

Grid 2 Directionof Wave Input

Ne1

Ne2

Ne4

Ne7

Ne3

S1

S2

S3

S4

S5

Ne5

Ne6

Ne8

Ne9

S6

S7Ne10

S8

S10

S9

S11

S12

Ne11

Ne12

Ne13

Ne14

Ne16

S13Ne17

Ne15

Grid 1Grid 1

Grid 2Grid 2

ChopawamsicCreek

ChopawamsicCreek

QuanticoCreek

QuanticoCreek

PotomacRiver

PotomacRiver

Figure 3-2. Location of STWAVE grids and data output stations. Figure 3-3. Index of plates used to display shore management recommendations and the shore reaches usedin the discussion of the reaches. 20

Figure 4-1. Geologic strata map of Marine Corps Base, Quantico. GIS data provided by Quantico.21

Reach 1A

Reach 1ATank Creek Mouth

Figure 5-1. Bank conditions recommended shore management structures for Plates 1 and 2. Segment number (shown in white) is for location reference only. The recommendation namematches, in color, its representative alongshore line. Photo base VGIN 2009.

22

Reach 1A

Reach 1B

Reach 1B

Reach 3B

Reach 2

Figure 5-2. Bank conditions and recommended shore management structures for Plates 3 and 4.Photo base VGIN 2009.

Segment number (shown in white) is for location reference only. Therecommendation name matches, in color, its representative alongshore line.

23

C

A

B E

Figure 5-3. Photos taken along Quantico’s shoreline in Reach 1. Photos taken on 5 Nov 2009 by VIMS personnel.

F

D G

H

I

Segment 2

Segment 1

Segment 5Segment 14

Segment 15Segment 10

Segment 4

Segment 23

Segment 21

24

MLWMHW (+1.4ft MLW)

Typical Revetment - Shore Segment 1

Bank Grading2:1

Typical Revetment - Shore Segments 7 & 8Typical Sill - Shore Segment 9, 10, 12, & 13

+30 ft

+7ft MLW+10 ft MLW

Freshwater scrub shrub+20 ft

25 ft

SAVScirpus

(intertidal species)

4 ft +4 ft MLW

Figure 5-4. Shore management strategy cross-sections for Reach 1A.

A

B

C

Typical Revetment - Shore Segments 2,3,4,5, & 6

+10 ft MLW

Bank Grading2:1

Railroad Bed

20 ft

+20 ft MLW

BankRock

20 ft

+10 ft+8 ft

MLW

20 ft

MLWMHW (+1.4ft MLW)

Ex. Bottom

BankRock

Railroad Bed

25

MLW

MLW

A

B C

4 ft +4 ft MLW

Typical Revetment - Shore Segments 16 and 17 ( High Bank)

+ 15 ft MLW

+ 6 ft MLW

Parking lot

Typical Revetment - Shore Segment 18 &19

+10 ft MLW

10 ft

Freshwater scrub shrubScirpus


MLW

Figure 5-5. Shore management strategy cross-sections for Reach 1B.

Typical Revetment - Shore Segment 20 & 21

+10 ft MLW

+4 to + 5 ft MLW

4 ft+3 ft MLW

10 ft10 ft



Ex. Bottom

Ex. Bottom

D

Typical Revetment - Shore Segment 23 & 24

+20 ft MLW

+2 ft MLW4 ft

+ 4 ft MLW

Storm Surge Frequency from FEMA

+6 ft MLW

Ex. Bottom

MLW

8.3ft for 100 year7.4 ft for 50 years6.5 ft for 25 years5.6 ft for 10 years



+8 ft MLW

+3 ft MLW4 ft

10 ft

26

Reach 2CReach 2AReach 2B

Reach 3A


Segment number (shown in white) is for location reference only. The recommendationname matches, in color, its representative alongshore line.

27

C

DA

B E

F

G

H

I


Segment 25

Segment 26

Segment 28

Inside Chopawamsic Creek




Segment 30

Segment 30

28

MLW

MLW

J

K

Parking Lot

+20 ft MLW

GradedBank 2:1

+4 ft MLW

4 ft+5 ft MLW

Typical Revetment (Free Standing - Shore Segments 25 & 27

MLW

10 ft Ex. Bottom

10 ft

A

+ 5 ft MLW

Typical Revetment - High Bank(Free Standing-Shore Segments 28 & 30)

Typical Sill - Low Bank(Free Standing - Shore Segments 29 & 30

+2 ft MLW2 ft

+ 4 ft MLW

Ex. Bottom

B

10 ft

Ex. Bottom

C

I

Figure 6-2 (cont.). Photos taken along Quantico’s shoreline in Reach 2.Photos taken on 5 Nov 2009 by VIMS personnel.

-3 ft MLW

LandwardLimit of

SAV

8 ft+10 ft MLW

2:1 Slope

Typical Revetment - Shore Segments 32 &33

Broken ConcreteMLW

10 ft

Ex. Bottom

D

Figure 6-3. Cross-sections of typical structures for Reach 2.

Segment 32

Segment 31

Segment 31

29

Reach 3B

Reach 3A

Reach 3C



37

38

30

Reach 3C

Reach 3D

Reach 3DReach 4A

Reach 4B



45

45

45

31

C

DA

B E

F

G

H

I


Segment 32

Segment 33

Segment 32

Segment 34

Segment 36

Segment 36

Segment 38

Segment 37

Segment 40

32

J

K

L

M

N

O

P

Q

R

Figure 7-3 (cont). Photos taken along Quantico’s shoreline in Reach 3. Photos taken on 5 Nov 2009 by VIMS personnel.

Segment 47

Segment 40

Segment 39

Segment 42

Segment 43

Segment 45

Segment 45

Segment 45

Segment 46

33

MLW

S

T

U

Figure 7-3 (cont). Photos taken along Quantico’s shoreline in Reach 3.Photos taken on 5 Nov 2009 by VIMS personnel.

+5 ft MLW

Cobble Beach

Ex. BrokenConcrete

3 ft

Typical Sill - Shore Segments 42, 43, & 44

+15 ft MLW

+3.5 ft MLW3 ft

Freshwaterscrub shrub

Scirpus(intertidal species)

MLW

10 ftEx. Bottom

A

B

MLW

Ex. Bottom

+5 ft MLW

+4 ft MLW +3 ft MLW

Typical Sill - Shore Segments 40 &41

Typical Revetment - Shore Segments 34, 35 & 36



+4 ft MLW

Ex. Bottom

10 ft

10 ft

Figure 7-4. Typical cross-sections for recommended structures in Reach 3.

Ex. BrokenConcrete

Typical Revetment - Shore Segment 47

6 ft

+5 ft MLW

2:1

10 ft

MLW

Ex. Bottom

Ex. Bottom

C

D

34

Reach 4B

Reach 4C

Figure 8-1. Bank conditions and recommended shore management structures for Plates 11 and 12Photo base VGIN 2009.

. Segment number (shown in white) is for location reference only. Therecommendation name matches, in color, its representative alongshore line.

5053

53

54

35

C

DA

B E

F

G

H

I


Segment 49

Segment 49

Segment 49

Segment 49

Segment 50

Segment 50

Segment 52

Segment 53

Segment 54

36

MLW

J

K

L

Figure 8-2 (cont). Photos taken along Quantico’s shoreline in Reach 1.Photos taken on 5 Nov 2009 by VIMS personnel.

A

C

Typical Breakwater - Shore Segments 51 &52

Typical Sill - Shore Segments 55 - Low Bank

3 ft+ 3ft MLW

4 ft+3.5 ft MLW

10 ft Ex. Bottom

MLW

10 ftEx. Bottom



B

Typical Marsh Planting: Shore Segment 56Eroding Marsh


MLW

10 ftEx. Bottom

MLW

10 ft Ex. Bottom

Figure 8-3. Typical cross-sections for management strategies recommended in Reach 4.

Segment 54

Segment 55

Segment 56

37

Figure 9-1. Bank conditions for Plates 13 and 14. No shoreline management structures have been proposed for thisReach. Photo base VGIN 2009.

Segment number (shown in white) is for location reference only.

Reach 5

Reach 5

Base ofBank

Condition

BankFace

Condition

Base ofBank

Condition

BankFace

Condition

57

60

62

64

59

58

61

66

68

38

Figure 9-2. Bank conditions for Plates 15 and 16.Photo base VGIN 2009.

Segment number (shown in white) is for location reference only. No shoreline management structures have been proposed for thisReach.

Reach 5

Reach 5

Base ofBank

Condition

BankFace

Condition

Base ofBank

Condition

BankFace

Condition

69

7273

74

70

71

39

C

DA

B E

F

G

H

I


Segment 57

Segment 58

Segment 58/59

Segment 59

Segment 60

Segment 67 Off Segment 66

Near Segment 69

Off Segment 71

40

Appendix A

Historic and Recent Aerial Imagery, Digitized Shorelines, and End Point (1937-2009) Rate of Shoreline Change

Appendix B

Base of Bank and Bank Face Conditions, Existing Structures, and Backshore Width by Reach and Segment Number

Appendix C

Table of Existing Data by Segment Number

Segmt Number Reach Priority^

Site Length

(ft)

Average EPR* (ft) Base of Bank Bank Face

Back Shore

Width (ft)Existing Structures Comments Landscape

Distance to 6ft Contour

(ft)

1 1A L 635 -0.4 Erosional Erosional NA None Wooded 1,4092 1A H 352 1.4 Transitonal Stable 10 to 15ft None Railroad tracks near eroding banks Wooded 1,4113 1A H 266 0.7 Erosional Erosional 10 to 15ft None Railroad tracks near eroding banks Wooded 1,3284 1A H 244 0.3 Erosional Erosional 0 In Situ Natural Bank Rocks Railroad tracks near eroding banks Wooded 1,2375 1A H 235 0.7 Erosional Erosional 5 to 10ft In Situ Natural Bank Rocks Railroad tracks near eroding banks Wooded 1,1446 1A H 63 0.9 Erosional Stable 0 In Situ Natural Bank Rocks Railroad tracks near eroding banks Wooded 1,1137 1A H 274 0.5 Erosional Erosional 5 to 10ft None Railroad tracks near eroding banks Wooded 1,0108 1A M 205 0.3 Erosional Erosional <5ft In Situ Natural Bank Rocks Wooded 9369 1A M 263 0.0 Erosional Erosional to Transitional 5 to 10ft None Wooded 854

10 1A M 576 0.1 Erosional to Transitional Erosional and Transitional 5 to 10ft None Wooded 64711 1A M 321 -0.7 Erosional Erosional 5 to 10ft None Low bank drainage Wooded 64712 1A M 329 -0.1 Erosional Erosional 5 to 10ft None Wooded 66513 1A M 608 0.2 Erosional Erosional 10 to 15ft None Vegetated Wooded 62314 1B L 187 0.7 Structure Present Erosional NA RipRap Base Infrastructure Pond 62315 1B M 257 0.3 Structure Present Structure Present NA Bulkhead Parking Lot 63216 1B H 429 0.0 Erosional to Transitional Erosional and Transitional <5ft None Wooded Bank / Parking 71717 1B M 289 -0.2 Erosional Erosional <5ft None Wooded Bank / Grass 85718 1B M 289 0.6 Structure Present Structure Present NA Concrete Wall Old concrete wall Grass 95319 1B M 290 0.3 Structure Present Structure Present NA Stone Wall Old stone wall Parking Lot 94020 1B M 205 0.6 Erosional Transtional to Stable 5 to 10ft None Wooded Bank / Grass 98421 1B L 323 0.5 Structure Present Erosional and Transitional NA Concrete Wall Old low concrete wall Wooded Bank / Grass 92722 1B L 255 0.4 Structure Present Transtional and Stable NA Crib Wall Wooded Bank / Grass 85823 1B M / H 383 0.4 Transitonal Transtional to Stable 5 to 10ft None Steep bank face Wooded Bank / Grass 67724 1B H 200 0.3 Structure Present Erosional NA Broken Concrete Wooded Bank / Parking 66625 2 H 420 0.3 Erosional Transitonal 0 None Wooded Bank / Parking None26 2 L 97 0.3 Structure Present Stable NA Bank Rocks Wooded Bank / Parking None27 2 H 395 0.0 Erosional Stable NA None Wooded Bank / Parking None28 2 M 480 0.0 Erosional Erosional to Transitional NA None Grade bank Wooded Bank / Grass None29 2 M 320 0.0 Erosional Erosional NA None Wooded None30 2 M 499 0.0 Erosional Erosional to Transitional NA None Wooded None31 2 L (SA) 657 0.0 Structure Present Structure Present NA RipRap New riprap Side Walks / Grass None32 3A M 3,204 0.2 Structure Present Structure Present NA RipRap Old riprap Grass / Airfield 9933 3A M 869 0.0 Structure Present Structure Present NA RipRap Grass / Airfield 18534 3A M 584 -1.6 Erosional Erosional NA Broken Concrete Intermittant Grass / Airfield 55835 3A M 645 -2.8 Erosional Erosional NA Broken Concrete Old broken concrete Grass / Airfield 1,08136 3A H 1,056 -3.5 Erosional Stable NA Broken Concrete Grass / Airfield 1,57837 3B L 892 0.8 Erosional and Transitional Stable NA Marsh Marsh / Grass 2,30338 3B L (SA) 1,461 5.9 Structure Present Structure Present NA RipRap New riprap Grass 1,88739 3C L 136 -2.6 Structure Present Stable NA Stone Wall Old stone wall Marsh 1,89440 3C M 438 -0.4 Erosional Erosional NA None Wooded Bank / Grass 1,65341 3C M 283 0.9 Structure Present Erosional and Transitional NA Broken Concrete Wooded Bank / Road 1,57642 3C M 180 -0.2 Transitonal Stable 10 to 15ft Beach Narrow beach Wooded 1,51043 3C M 346 -0.1 Structure Present Erosional NA Broken Concrete Wooded 1,30444 3C M 259 -0.1 Erosional to Transitional Transtional to Stable <5ft None Wooded 1,150

45 3D L (SA) 2,421 -0.1 Structure Present Erosional and Transitional NA Concrete Wall Wooded Bank / Grass / Parking Lot 299

46 3D L 172 0.6 Stable Stable NA None Grass 41047 3D M 286 2.5 Structure Present Structure Present NA Broken Concrete Wooded / Parking Lot 35648 3D L (SA) 2,040 0.0 Structure Present Structure Present NA Bulkhead Marina / Bulkhead 57

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^L-Low Priority, L(SA)= Low Priority/Structure Adequate, M=Medium Priority, H=High Priority *End Point Rate was calculated between 1937 and 2009

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Segmt Number Reach Priority^

Site Length

(ft)

Average EPR* (ft) Base of Bank Bank Face

Back Shore

Width (ft)Existing Structures Comments Landscape

Distance to 6ft Contour

(ft)

49 4A M 879 0.4 Stable Stable 5 to 10ft Old Mill In Town of Quantico; Concrete/Stone wall failure in places Grass 371

50 4B M 1,291 0.0 Structure Present Erosional and Transitional NA Concrete Wall Beach in front in some sections Wooded Bank / Grass 5851 4B M 245 -0.7 Erosional to Transitional Erosional to Transitional NA None Scattered broken concrete Grass 4952 4B M 282 -0.3 Transtional to Stable Transtional to Stable <5ft None Wooded Bank / Grass 5153 4B L (SA) 543 -0.2 Structure Present Erosional and Transitional NA Concrete Wall Wooded Bank / Grass 254 4B M 168 -0.1 Structure Present Erosional NA Crib Wall Wooden crib wall that is decaying Wooded Bank / Grass 355 4C M 612 -0.3 Transitonal Transitonal 5 to 10ft Broken Concrete Down trees and broken concrete Wooded Bank / Parking 80

56 4C M 972 0.0 Erosional to Transitional Erosional to Transitional <5ft Broken Concrete Intermittant broken concrete and low bank face Marsh / Wooded 79

57 5 L 1,624 1.4 Transtional and Stable Stable NA Marsh Marsh None58 5 L 940 0.2 Transtional to Stable Stable <5ft None Wooded None59 5 L 485 -0.1 Erosional Stable <5ft None A couple of spots of bank rock Wooded None60 5 L 994 -3.0 Transtional and Stable Stable NA Marsh Wooded None61 5 L 550 -0.4 Stable Stable NA None Wooded None62 5 L 197 -0.2 Erosional Erosional NA None Wooded None63 5 L 483 0.0 Stable Stable NA None Wooded None64 5 L 219 -0.2 Erosional Erosional NA None Wooded None65 5 L 277 0.0 Stable Stable NA None Wooded None66 5 L 227 -0.1 Erosional Stable NA None Wooded None67 5 L 276 0.1 Stable Stable NA None Wooded None68 5 L 390 0.1 Erosional Erosional to Transitional NA None Wooded None69 5 L 350 -0.2 Erosional Transitonal NA None Wooded None70 5 L 762 -0.3 Erosional Erosional to Transitional NA None Wooded None71 5 L 1,416 -0.3 Erosional to Transitional Transtional to Stable NA None Wooded None72 5 L 377 -0.6 Transtional to Stable Stable 5 to 10ft None Wooded None73 5 L 324 -2.5 Transtional and Stable Stable NA Marsh Wooded None74 5 L 892 -1.1 Erosional Transtional to Stable NA None Wooded None

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^L-Low Priority, L(SA)= Low Priority/Structure Adequate, M=Medium Priority, H=High Priority *End Point Rate was calculated between 1937 and 2009

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